TGFB1 and COVID-19: Furthermore, studies on serum of COVID-19 patients have recommended assessing TGF-α, IFN-γ, TGF-β, IL-1, and IL-10 because of their association with the severity of the disease [39–41], however, importantly the role of these immune mediators as part of nasopharyngeal mucosal immunity against COVID-19 has yet to be established.